In a computer system, a correctable error (CE) detected in the L2 cache (second-level cache), is recoverable using ECC (Error Correction Code) correction to correct the data. For an uncorrectable error (UE), however, the ECC correction cannot correct the data. It is the responsibility of the hardware to ensure that the data is not used.
One way to accomplish this is to Checkstop the system (ie. stop the system and restart all pending jobs). With cache designs becoming more complex and more dense, there is an increasing probability that UEs will occur. It is important for these systems to keep running, even if a few jobs have to be abended, so it would be desirable to keep the system running in spite of UEs which have traditionally caused a checkstop of the system because of the indicated hardware error.